Typewriting machine



Nov. 3, 1936. J. A. B. SMITH TYPEWRITING MACHINE Filed Nov. 15, 1955 atented Nov.. 3,' 1936 ,PATENT 2,059,615 v 'EYPEWRITING MA Application November 15, 1933, Serial No. 698,063

6 Claims.

rilhis invention relates to the -keys ci typewriting machines. Y

For many years glassY nger-keys havel been used, because the hardness of the glass prevents it from being scratched or marredby the iingers of the operator.v This quality has rendered the keys specially valuable for use on trial machines, since, when the trial machine is returned to the manufacturer, its glass keys retain their 10 original polished condition. VIt has been a Aconstant objection` to glass keys, however, that they are held in place by annular metal key-caps,

, which have inturned overhanging flanges to ,hold

the glass disks down Vin the key-lever cups.

These anges project considerably above the glasskey-disks, andpunlshthe lingers or the operators.

Many operators'prefer to use a key which is molded in one piece and placed upon the keystem, and many machines have accordingly been provided with such molded keys.

An objection to the molded key is that, being made of celluloid,f shellac, or the like, it is apt to become scratched or defaced, and it is not de sired to put outv machines on trial that have the molded keys. The molded keys have an advantage that their tops are concave, but they have a further disadvantage that they are easily ignitible, for which reason a prejudice exists against them. Some kinds of molded keys are apt to become misshapen from usage or from heat.

It is a feature ci the present invention to provide the key-levers with keys which are not open to the foregoing objections. A celluloid concaved character-disk isla part of each oi the three forms of the invention disclosed, but it is notin the old objectionable form oi an exposed molded head. In each instance, the character- 40 disk is confined within the walls oi a usual metal key-cup.' mounted upon the key-stem oi the I Underwood standard typewriting machine. Other kinds or molded material may be employed as a substitute for cellulcid.

1n one form ci the invention, the characterdisk has a crown which is molded with a central concave broad area, and it also has 'a bottom proiecting brim, which supports an inturned cap or clip which holds the character-disk upon the 5o key; said character-disk being supported by an anti-friction device in the form oi a bed or disk oi cardboard or the like, hlling the bottom of the cup. The concave top of the key is only slightly below or is. substantially ush with the ridge of the inturned clipping dange, so that said ridge forms a continuation of the concaved key-suriace, and the projecting ridge is not felt by the finger when placed upon the concaved charac ter-disk.

o0 in @ed term or the invention, the

(Cl. 19t-102) acter-disk is concaved, and the inturned clipping flange of the cap is made level with the key, and rests upon the projecting brim that borders the character-disk, and, by its downward pressure, holds the brim and disk down upon the base or g support. Y

The inammable celluloid is protected against ignition by being coniined within the metal cup and being overbordered by the metal key-cap, and it is also protected from being scratched.- orlo marred.

Other features and advantages will hereinaiter appear.

The accompanying drawing shows three forms oi the invention, depicted in three groups, of 15 which the rst group is marked Figure l, the second group is marked Figure 2, and the third group ismarked Figure 3. 'I'he upper portion of each group shows in vertical section the key which is seen in perspective in the lower part ci 2o the group, accompanied` by perspectives oi the key-elements.

Referring to Figure l, it represents a key-lever having a stem. ii, upon which is xed a dat socket-portion it of a key-cup of ordinary construction, which includes a loor it and annular shell or side portion it. The key-disk i is l formed of `ioined layers of celluloid, the lower layer it having impressed thereon a character il, and the upper layer it being transparent and y@ exceptionally thin, and hard, to resist scratching.,

This disk is shown fiat in detail perspective, but it is concave within the cup it, it, as shown insection. In the bottom of the cup isplaced a metal ring it, which iits within the cup-shell gg it and' forxns an annular seat for the key-disk ih.

The disk is held on by an annular cap, having 'sides or shell it and ears 2 i which clasp or fasten under the bottom of the cup it.

The brim it of this cap overiies the border oi an the key-disk, and is concaved sufficiently to produce forced concavity of the exible key-disk, as indicated at it; both the key-disk and the cap it being concave; the concavity of the brim being indicated at it. The disk may be placed at upon the annular seat in fiat condition, and .may be given the illustrated concaved contour by means of the downward' pressure oi thekey-cap thereon; although in some cases the compound key-disk may be molded in the concave form so before being placed in the key.

The cap-brim di holds the key-disk permanently under compression, inasmuch as it forces the border oi the'disk downv upon the annular seat and presses the latter down against the bot- 55 tom of the cup, and sufficient friction is engendered to prevent the key from accidentally rotating while in use. 'Y

In the grouping shown at Figure 2, having the same key-lever stem and key-cup il, it, it, it, to

a two-ply molded celluloid disk is formed with a broad central concaved portion 25, bordered by a brim 26. In construction, the key disk is similar to I5; but, instead of being used in flat condition, it is molded into shape prior to being placed in the cup.

The key-cap, having annular form 27, is formed at the top with an inwardly-rolled bead 28, which overlies the edge I4 of the key-cup and extends inwardly beyond said edge, and seats down upon the brim 26, and holds the same down upon a bed 29, which may consist of a thick cardboard disk; the key-cap being held down firmly by the clips or ears 2|, and by its downward pressure clasping the brim 26 down upon the support or bed 29. In order to avoidpunishment of the finger-ends, the bead 28 may lie in the same surface as the concave portion 25 of the keydisk; this advantage being enhanced by rounding the flange 28 of the key-cup, as shown at Figure 2. The disk 25 may be made of two layers Yof Celluloid, the upper one transparent, and the lower one having a character thereon, as seen at Figure 1, and may then be molded as seen at Figure 2.

`At Figure 2, the key-disk 25, 26 is prevented from rotation during use, by reason of the downward pressure which the key-cap permanently exerts upon the disk, to force it down upon the cardboard bed, producing friction between the two disks and also friction between the bed-disk and the bottom of the key-cup. The two disks are constantly held in this clamped condition, so that rotation is prevented. The cardboard is somewhat yielding and affords an eiiicient frictional support for the purpose.

In the group shown at Figure 3, having similar key-cup I2, I3, I4, the character-disk with its transparent top is broadened, and this disk and its top are flush, with the top 30 of the key-cap 3|. The key-cap 30 is fiat, with a somewhat rounded corner 32; and this forms a key which is agreeable for the fingers to touch. The cap 30 extends only a little beyond the edge I4 of the key-cup, and the key-disk is molded with a projecting brim 26. The latter is bedded upon a cardboard disk 34 as at Figure 2; and the pressure of the cap 30 holds the brim 26, character-disk or crown 25, the cardboard and the cup-oor tightly together in the manner already explained with reference to Figure 2.

It will be seen that after the machine is constructed, its key-cups may be equipped with any one of the three forms of the concaved character-disk fittings above described. Caps may be removed from keys of any completed machine, and the character-disks may be removed and replaced by any other set of character-disks and supports.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. A typewriter-key having a key-cup, a crown of molded material provided with a character, a brim projecting from the bottom of said crown and confined within said cup, and an annular cap applied upon said cup and having an inturned flange, and pressing downwardly to hold said flange down upon said brim, the latter being supported against the downward pressure of said cap, the crown being substantially iiush with the top of the cap.

2. In a type-operating key for a typewriting machine, the combination with a character-bearing crown of hard molded material surmounting a bottom brim integral therewith, of a support, and an annular cap enclosing the brim and having an internal iiange pressing down upon said brim, said crown fitting within said cap and rising through the same, said cap being co-operative with said support to clip said brim tightly down upon said support; said crown being substantially ush with the top of said cap, to afford a broadening of the striking surface of the key.

3. In a type-operating key for a typewriting machine, the combination with a characterbearing crown surmounting a bottom brim, of a support, an annular cap enclosing the brim and having an internal flange pressing down upon said brim, said crown fitting within said cap and rising through the same, said cap being cooperative with said support to clip said brim tightly down upon said support; said crown being substantially flush with the top of said cap, to afford a broadening of the striking surface of the key, said support being in the form of a cup, and a friction disk of relatively yieldable material confined in said cup and supporting said brim and crown, and subject to the specied downward pressure of said brim, to prevent accidental rotation of said crown.

4. A typewriter-key having a key-cup with provision for mounting upon a key-stem, a character-disk in the form of a two-ply crown of cel/luloid provided with a character and including a brim projecting from the bottom of said crown, and an annular cap clasped upon said cup and having an inturned flange pressing downwardly upon said projecting brim, the brim being supported against the downward pressure of said cap, and the cap being flush with the top of the crown, said two-ply character-disk being molded with a central concaved broad character-bearing area, and including as its top ply a thin shaped disk of transparent celluloid having a crownportion and a brim-portion.

5. A typewriter-key having a key-cup with provision for mounting upon a key-stem, a twoply crown of transparent and opaque celluloid, the opaque ply being provided with a character, a brim projecting from the bottom of said crown, and an annular metal cap clasped upon said cup and having an inturned flange for retaining said brim and pressing downwardly thereon, the brim being supported against the pressure of said cap, the celluloid being protected against ignition by the metal key-cap, and the crown being flush with the top of the cap, said character-crown being molded with a central concaved broad character-bearing area, and the upper ply being the transparent celluloid.

6. In a typewriting machine, the combination of a key-cup, a character-disk formed with a crown and a brim, and a key-cap secured to said cup and having an inturned ange holding said brim down upon said cup, said flange being flush with said crown and affording a broadened expanse of lnger-striking surface.

JESSE A. B. SMITH. 

